Jamian, 59, was hired in June 2011 for a second stint as the authority's executive director. He also had the job from 1997 to 2001.

"I accomplished everything I needed to accomplish in three years," Jamian said.

When asked whose decision it was for him to leave, Jamian would say only that his deal was for three years and that he has other work he wants to do.

Jamian said he intends to work with the nonprofit Detroit Wayne County Port Foundation that aids the port authority in maritime education, preservation, environmental stewardship and other functions.

"I'm going to work to make that financially strong," he said.

He didn't specify whether that would be paid or volunteer.

During Jamian's tenure, the authority completed construction of a $15 million, 21,000-square-foot ship terminal and $7.1 million offshore wharf to serve cruise ships and other deep-draft vessels in the Detroit River bringing tourists (and their money) to the city.